package com.example.mobifin_busticket;

import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import android.util.Base64;

public class AESEncoder
{
	private SecretKeySpec keyspec;
	private Cipher cipher;
	private String SecretKey; 

	public AESEncoder(String secretKey)
	{
		this.SecretKey=secretKey;

		keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES");

		try 
		{
			cipher = Cipher.getInstance("AES/ECB/NoPadding");
		}
		catch (NoSuchAlgorithmException e)
		{
			e.printStackTrace();
		} 
		catch (NoSuchPaddingException e) 
		{
			e.printStackTrace();
		}
	}

	public String encrypt(String text) throws Exception
	{
		if(text == null || text.length() == 0)
			throw new Exception("Empty string");

		byte[] encrypted = null;

		try 
		{
			cipher.init(Cipher.ENCRYPT_MODE, keyspec); 
			encrypted = cipher.doFinal(padString(text).getBytes());
		}
		catch (Exception e)
		{                       
			throw new Exception("[encrypt] " + e.getMessage());
		}

		String base64 = null;
		try
		{
			base64 = Base64.encodeToString(encrypted,Base64.DEFAULT);
		}
		catch (Exception e1) 
		{
			e1.printStackTrace();
		}

		base64 = base64.replace("+", "-");
		base64 = base64.replace("/", "_");
		base64 = base64.replace("=", ",");

		return base64;
	}

	public byte[] decrypt(String code) throws Exception
	{
		if(code == null || code.length() == 0)
			throw new Exception("Empty string");

		code = code.replace("-","+");
		code = code.replace("_","/" );
		code = code.replace(",","=");

		byte[] base64Decrypted = Base64.decode(code.getBytes(), Base64.DEFAULT);

		byte[] decrypted = null;

		try 
		{
			cipher.init(Cipher.DECRYPT_MODE, keyspec);

			decrypted = cipher.doFinal(base64Decrypted);
		} 
		catch (Exception e)
		{
			throw new Exception("[decrypt] " + e.getMessage());
		}
		return decrypted;
	}

	public static String bytesToHex(byte[] data)
	{
		if (data==null)
		{
			return null;
		}

		int len = data.length;
		String str = "";
		for (int i=0; i<len; i++) 
		{
			if ((data[i]&0xFF)<16)
				str = str + "0" + java.lang.Integer.toHexString(data[i]&0xFF);
			else
				str = str + java.lang.Integer.toHexString(data[i]&0xFF);
		}
		return str;
	}

	public static byte[] hexToBytes(String str) 
	{
		if (str==null) 
		{
			return null;
		}
		else if (str.length() < 2) 
		{
			return null;
		}
		else 
		{
			int len = str.length() / 2;
			byte[] buffer = new byte[len];
			for (int i=0; i<len; i++) 
			{
				buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16);
			}
			return buffer;
		}
	}

	private static String padString(String source)
	{
		char paddingChar = ' ';
		int size = 32;
		int x = source.length() % size;
		int padLength = size - x;

		for (int i = 0; i < padLength; i++)
		{
			source += paddingChar;
		}
		System.out.println("====>Pad String:"+source);
		return source;
	}
}
